Sheet-feeding machine



UNITED STATES PATENT OFFICE.

EDWIN F. HULBERT, 0F MILWAUKEE, WISCONSIN, ASSIGNOR TO NATIONAL PAPER CAN COMPANY, OF MILWAUKEE, WISCONSIN, A CORPORATION OF DELAWARE.

SHEET-Famine MACHINE. f

Application filed December 27, 1917.

T0 all 'zo/ioni. it may concern.

Be it known that I, EDWIN F. HULBERT a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented a new and useful Improvement in Sheet-Feeding Machines, of which the followin is a full, clear, and exact description o same, reference being had to the accompanying draw ings, forming part of this specification, in Whieh1 Figure 1 is a side elevation of the sheet feeding machine embodying the present invention.

Fig. 2 is a detailed view of the feeler and contact box.

Fig. 3 is a section on the line III-III of Fie. 2.

i 4 is a horizontal. section along the line TVIV of Fig. 1, and l Fig. 5 is a diagram of the electric circuits.

The present invention relates to machines for feeding -sheets of paper or the like and more particularly to machines for feeding sheets of paper singly from a pile or stack of sheets. In machines of this type the top sheet is Separated from the pile by a suitable transferring mechanism and transferred to the feeding rolls of the machine which has to operate on the sheets. It is desirable to have the top of the pile of sheets maintained at a substantially constant level With relation to the mechanism which transfers the top sheet from the pile. The present invention relates particularly to a simple but accurate device for so maintaining the top of the piles of sheets at a substantially constant level.

Referring to the drawing, a pile of sheets of paper or the like 2 is carried on a vertically movable table 3. A vacuum foot or suction device 4 is arranged to be lowered against the top of the pile of sheets and to lift the top sheet and transfer it to feeder rolls, which carrygthe sheet to the machine to be fed. The construction and operation of the means 'for transferring the top Sheet from the pile which includes the vacuum foot 4 and feed roll 5 is Well known in this art and is not here described in detail. The vacuum lifting foot is preferably of the forni shown in the patent of Carl Willard Krueger No. 1,250,902 of December 18, 1917 for slavo@ feeding machines.

Specification of Letters Patent.

Patented Aug. 10, 1920.

Serial No. 209,187.

-The invention relates to the means for maintaining the top of the pile of sheets 2 at a substantially constant level with relation to the sheet transferring means, one embodiment of which is shown in the draivings and is described as follows: The table 3 is mounted in carriers 10 which are arranged to be moved up and down the legs 1l. The legs 11 are provided with racks 12 engaged by pinions 13 on the carriers 10. The pinions 13 are driven, by an electric motor 14 through speed reducing gearing including a Worm 15 on the motor shaft engaging a Worm gear wheel 16 carried on the shaft of one of the pinions 13. The pinions 13 are connected by means of a chain 17 carried by sprocket wheels on the pinion shafts. The motor 14 is sup oited on the underside of the table 3. he table is adapted to be raised gradually by the motor 14. y

The motor is controlled by a feeler 20. The feeler 20 consists of an anti-friction roller 21 carried on the end of a pin 22 vertically movable in a contact box 23 and resting lightly by gravity against the top of the pile of sheets. The Contact box 23 is carried by a fixed frame 24 over the top of the table. The side of the pin 22 is provided with a rack 30 which meshes with a pinion 31 formed on the hub of a movable Contact arm 32. The free end of the arm 32 carries a movable Contact 33 which is arranged to engage a fixed contact 34. The contacts 33 and 34 are connected by lead Wires 35 to a relay 3G which controls the feed circuit of the motor 14.

The operation of the device is as follows: Suppose that the feeder is operating and the top sheet transfer means 4 and 5 is continually transferring sheets from the top of the pile. lhen the top sheet is removed the feeler 2l moves downwardly the thickness of the top sheet and rests on the sheet iininediately below. The downward movement of the feeler roller 21 ermits the contacts 33 and 34 to come toget er and through the relay 36 to switch on the current for operating the motor 14. The motor 14V thereupon raises the table with the' pile of sheets until the feeler rises and separates the contacts and 34 whereupon the motor stops and the table is stationary. If sheets of moderately thick material are being fed, the contact device will operate upon the removal of each toi: sheet. ll the sheets are oil thin niaterial the removal ol:A several sheets may he necessary hel'orc the feeler drops endif-lent to bring;r the contacts :lill and 3l inlo engagw ment to start the inotor.

The device will operate without change of adjustment 'for sheets ol" any thickness as the movement of the taille is controlled solely by the feelinh Which engages the top of the pile. The machine-nay be adjusted to very accurately maintain the level of the top of the pile olf sheets. l? or example, in one .machine huilt, the top oi' the pile of sheets Inay he maintained within seven thonsandths of an inch of a fixed level. ln the illustrated embodiment of the invention the level of the sheet transferring means l and 5 fixed while the Sheet hold ing, table Il moved. lt is ohvions that hy mei-e reve l might be Yil of parte the table l; ixed and the sheet transferring mechanism l and 5 he inoved dmvnwardly and iis posh tion controlled hy a i'eeler engaging the iop of the pile of sheets on the table. 'lf he in vention is not lii'nitcd to the movement of' the table alone hut is intended to include 'the relative vertical movement between the table and sheet transferring means whereby the top of the pile and the sheet transferring means are maintained at a substantial ly con stantlevel with relation to each other.

A hand reversing switch tl0 is 'provided hy means of which the motor l-l driven in the reverse direction to lower the table when a fresh pile of sheets is to he placed on it.

W'hiie the preferred embodiment ol: the invention has been illustrated it is to he nnderst'ood that the invention is not limited to its preferred einhmlinient but may he ein bodied in other constructions of sheet feeding apparatus Within the scope of the 'following claims.

fl claim:

l. ln :i machine lor feeding sheets of paper or the like from a pile having means for transferring the top sheet from the pile, the combination oi' a freine having legs with racks formed thereom e table having pinions engaging the racks and means for relatively raising the table with relation to the transferring means to maintain the top of the pile at a substantially constant level with relation to the transferring ineens, comprising an electric motor carried 'on the table and operatively connected to drive the pinions, and means lor controlling the motor including; a feeler adapted tn rest against the top of the pile` -nid an electric Contact moved bv the i'ccler and operating" to start the motor when the ieeler moves downwardly upon the removal of the top sheet or sheets and operai Le" to Stop the motor when the top of the pi of sheets is raised to the desired ,n-mlete::nined level; slihstiintinlly the 2, ln a machine for Vfeeflini'g Shimis ol paper or the like l'roin a pile hai. ingr incam iol' transferring the top #hoot 'from the pile.,y the combination ol' a traine having' a phi rzility o l' lege, :i taille haring` mechanism ein raging the legs lo raise the taille with relation thereto, an eier-trie motor carried lily the l'ahlc for driving the table raising i'neolin nism and meanslor controlling the Vmotor to maintain the top of the pile at a substantially constant level with relation to the transferring means, including a feeler adapted lo reet against the top of the pile, and an electric Contact moved by the feeler and opn mating to Start the motor when the feeler moves downwardly upon the removal of the top sheet or sheets and operated to Stop the motor when the top ol' the pile o'i' sheets raies-xl to the desired. predetermined level g substantially descriliei'l.

1?. in a machine for teething sheets of papel' or the like it'roin a pile having means for transferring the top sheet from the pile, the roinhinaiion of a table Vlor holding the pile Voif sheets, mechanism for relatively moving the table with relation to 'the transu tcrring means, including an electric mot-or, and means for controlling the motor includ ing a shaft having an electric contact arm carried thereby, a gear on the shaft, and a Ji'eeler adapted to rest aga-inst the top of the pile and having a rack meshing with the gear, said Contact and 'feeler mechanism operating to start the inotor when the leeler moves downwardly upon the removal of the top sheet, or sheets, and operating to stop the motor when the top of the pile of ,sheets ie raised to the ileeired predetermined level; substantially as described.

i. .ln a. machine for feeding Sheets of paper or the like from a pile having ineens for transferring the top .sheet from the pile, the combination of a table for holding the pile of sheets, mechanism for relatively raising the table with relation to the transferring means, ii'icluding an electric motor car-- ried Aon the table and irreversible speed. reducing gearing driven thereby and engaging a stationary part of the machine, and nie-ans for controllingI the motor, including a ieeler adapted to rest against the top of the pile, and an electric Contact and e motion increasing:r connection between the feeler and the Contact, said feeler and contact operating to start the motor when the eeler moves dmvmvardly upon the removal of the top sheet or sheets and oj'ierating to stop the motor when the top of the pile of sheet@l is raised to the desired predetermined level; substantially as described.

5. A machine for feeding sheets of paper or the like from a pile l'iavingmeans for transferring the top sheet from the pile, the coinl'iination of a table for holding the pile J' cherie, mechanism for relai'ivelv raising:

the table with reaisun o the transferring means, including a (ge-.fw and an electr motor having a worm, piuma engaging said gea? to form au irc zrsble transmission holding the table agans downward move merit by gravity whcn the motor is stopped, und, means for mmm-.Bing the tabe raising mechanism including; u, eeler adaped t@ m55 against the top of the pile, and an eectrc. conat moved by the feelel and. operating to start the motor when tha feder moves downwardly upon the removal @E ilu, top simi-t1 Uf Shefc'tfig, und operating; 'm awp tifs. mami- 'wwn the op of tha pe u :shawls if .raised tu the desired rIl)iwriii-,lmnali kwel; aubstzmiqly as descbed.

n etmmay wheivm 'I lmvf; hereunto sei my rmnd.

EDWN F. HULBERT. 

